I bought an Autoprop H5-394 last year. I installed it earlier this spring, and just pulled my boat for the winter and inspected the prop.
First, I have to say that It is obvious that I get more speed and power at the same RPM as my old fixed three blade prop, and I know I get better NM/gallon now.
When I inspected the blades, I noticed one tip is slightly bent. Then I noticed that my cutlass bearing support can be contacted by my blade tips (and one did). I tried to review all earlier notes on this topic, and noticed that the "recommended solution" is to grind clearance in the bearing support strut to eliminate the interference potential. As anyone done this? Did anyone have any problems after doing it? I have about a 5/8 inch interference point.
Alos, I get a loud rumble/vibration when I try to puch my boat speed up over 7 knots at above 1950 RPM. Do any other owners have vibration problems at rpm ranges from 1900 - 2300?
Thanks,
Ken Enstrom
2004 C-36 MKII #2199
Tall Rig, Wing Keel, M-35B
S/V Valkyrie - Sail Great Lakes
Ken,
I cut a small notch in the prop strut in both my C36 and my C400 for my autoprops. In both cases it worked perfectly. It's kind of important that the prop not contact anything as it spins! With the prop nut tightened, I made sure there was at least 1/8" clearance between the prop and the strut throughout the full swing of all three blades. As far as the vibration goes, I think you may have to send the prop back to the factory to have it straightened and re-balanced. You might have noticed that each blade has a serial number. They do that for a reason. Each blade is matched to the other two on your prop, and my guess is that you've messed up the balance. Sorry.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Tom - Thanks for the info. I've always appreciated your contributions to this forum. I guess it is time to get out the grinder and put my 5/8 inch notch in the cutlass bearing support. (I never got comfortable drilling holes in my hull either -- just an uncomfortable feeling....................)
Attached are a pic of the blade tip and the interference. Not sure if that amount of bend could be causing my "rumble" sound or not, and I recall that I noticed the rumble right away after installing whenever I went above 1950 doing a quick stop in reverse, etc
Ken Enstrom
2004 C-36 MKII #2199
Tall Rig, Wing Keel, M-35B
S/V Valkyrie - Sail Great Lakes
Ken,
That does seem like a very small nick on the blade. Not sure it would cause the rumble you mentioned. But, because the alloy they use for the autoprop (VERY hard!) has so little give, you might have done something to the bearings or bearing races inside. I know it's a royal pain shipping stuff to AB Marine, and then they ship it to the UK, but it might be the best course of action. Another couple of possibilities I just thought of. Have you checked your cutless bearing lately? Any play in that could cause a rumble. Do you have a SS (Aquamet) or bronze shaft? I found that the bronze OEM shaft was too soft for heavy props like the autoprop. If a bronze shaft gets even the tiniest bit out of true, the heavy prop at the end of it can cause "shaft whip" or some such term. Have you checked engine alignment? Even though I bought a used autoprop for my C36, once the engine was aligned, cutless bearing replaced, notch cut in the prop strut, and a SS shaft installed, it was smooth through the entire RPM range. Not sure if this helps or not, but it might give you some more things to check. BTW, I would think that all props would cause a rumble when doing an emergency stop. You have tons of cavitation down there, and you're not running through smooth water. Just a thought.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Ken, I also have a Autoprop H5 and have a similar vibration around 2000 RPM. In my case, it usually subsides a bit after a few minutes and tends to be less of a concern. I hauled out this spring and replaced the cutlass bearing as it was badly worn. I also aligned the engine and cleaned the prop, installed new zincs etc. I had a mechanic examine it during a sea trial and the 2000 + RPM vibration was still there. His thought was that it was simply cavitation and not much to do about it. A further bit of information in my case was I ran the engine at well over 2000 during a run through a pass with strong currents and there was no vibration at 2000 or higher. Perhaps the fast flowing current prevented the bubbles and thus supports his theory of cavitation?
I bought the boat with the autoprop installed and someone has indeed carved a groove out of the strut (attached). They also installed a spacer at the flange-transmission connection which pushes the prop further out and away from the strut as you can see in the photo. Apart from the vibration which does subside, I like the autoprop. It provides good propulsion and backing up the boat is quite easy.
Hope that helps a bit.
Stephen Cameron
Stephen Cameron
2001 Catalina 36 MKII hull#2012
Tall Rig Fin Keel
Vancouver, BC
Additional clarifications --
- Cutlass bearing appears to be rock solid. Kind find no play.
- Have stainless steel shaft. Bought boat used, so either PO changed it, or 2004 models came that way.
- Checked shaft alignment myself in 2009 when I got the boat and it mesured in spec., but will check again next spring after mast is in and tuned, and boat is in water. Normally I store outside without mast removal as I have good winter cover.
Talked to Geoff at AB Marine. He thinks my rumble is cavitation and after reading your comments, I am thinking that is what I am hearing. I only get it when I try to stop (probably too fast) in reverse, or when I try to push the boat up around max hull speed.
I am sending AB Marine the blade pic and will go from there on what to do with the bent tip. Other than that, I will grind out 5/8 inch clearance in cutlass support, check shaft alignment after commissioning, and probably assume my rumble is cavitation.
Thanks so much for sharing your knowledge, experience, and ideas. The c36ia association is a great resource for me, and I try to help others when and where I can as well.
Good sailing mates.
Ken Enstrom
2004 C-36 MKII #2199
Tall Rig, Wing Keel, M-35B
S/V Valkyrie - Sail Great Lakes
Just wanted to add that I think the bent tips will definitely cause the rumbling you mention, but the guys at AB should be able to sort it out. If you can I would also follow Tom's advice and send the prop in for servicing. I have no issues at any rpm up to 2800 and I never go much above 2300 as I reach hull speed at 2150 to 2200 usually... Bronze shaft, but no problems noted.
---- Howard & Linda Matwick ----
--- S/V "Silhouette" - Nanaimo, BC ----
--- 1999 C36 MkII #1776 M35BC ---
Installing an AutoProp is also an option on my list to replace the standard 3-blade 15x9 RH propeller.
I read in this threat a model number H5-394.
The model I received as recommendation from Brunton is H5-416, so a larger diameter.
Looking to the pictures it seems anyhow needed to make a small modification to the bearing support strut to create sufficient clearance.
Which gearbox ratio do the Catalina's have with their AutoProp propeller?
I have now A=2.14:1 (ZF-12M) which might explain a bigger diameter compared to the original A=1.79:1
In the documentation I see that AutoProp propellers can be supplied with different bosses 70, 90 and 120mm which could be used to move the propeller more to the aft.
Is there any info available which bosses on the AutoProp is in use of your Catalina?
I am a little bit afraid that with a bigger diameter too much of the bearing support strut needs to be grinded away when the wrong specs are given.
Also I am not sure about the cone-size of the standard 1" brass propeller shaft. In Europe we have standard cone of 1:10.
Is the cone the standard 1"-SAE?
Anyhow it is good to read that the AutoProps are performing well and worth a try, despite the serious higher costs compared to the alternative feathering / folding props. I am keen to order.
Normally this would be a nice winter-job when I have our Siler in our shed to swap with sufficient time to make measurements and ordering, but I got a good price offer and there is not much time left at this moment to haul the boat out and to make measurements / checks.
Thanks in advance for sharing your knowledge.
Durk Nijdam
S/V "SILER"
Catalina 36MKII - 2001 / hullnr. 2013
Stavoren - Holland
Durk -- I am very happy with my Autoprop. I was also concerned about grinding some of the strut shaft support away to provide celarance when the autoprop flips from forward to reverse. However, I did grind away the clearance and I have had zero problems. The amount I ground away was an arc tha was only about 1 inch long and 0.5 inch deep. The support strength was not impacted in any way and all has been good. I took a marker and traced the clearance I needed on the strut with the blade in the farthest forward position and then ground out that area. Everything has been good ever since.
Ken Enstrom
Ken Enstrom
2004 C-36 MKII #2199
Tall Rig, Wing Keel, M-35B
S/V Valkyrie - Sail Great Lakes
Hi Ken, it is good to hear that the impact is not that a big issue and that the experiences are good with this propeller type.
Do you still have the orginal ZF-100 transmission fitted? This with respect to the different size which is offered to me.
Anyhow I made a pre-ordered for the bigger sized AutoProp H5-416 with the agreement to make proper measurements with a template when I have our Siler back in our shed for the winter and to check which size of boss would be most convenient to minimize the amount of grinding required to the strut.
Thanks a lot for sharing your information.
Durk Nijdam
S/V "SILER"
Catalina 36MKII - 2001 / hullnr. 2013
Stavoren - Holland
I have the original transmission that came up with my boat as far as I know. I bought it form the original owner who only had it for 2 years.
Transmission is model ZF10M, S/N 24001, part # 3304002004; A= 1.79, B=1.86
Propeller – Autoprop H5-394-RH RB TS (RH=right hand, RB=roller brg?, TS= taper shft?; S/N AP7354RH
Above are my notes of the specs for my transmission and autoprop.
Good Luck
Ken Enstrom
2004 C-36 MKII #2199
Tall Rig, Wing Keel, M-35B
S/V Valkyrie - Sail Great Lakes
Hi, I've had an H5 autoprop for years. It is super important to fill the 3 grease channels every lift out. My prop was about 9 years old when it developed a vibration that soon wore out the cutlass bearing. I was cleaning the underside and prop when one blade literally came off in my hand! The tapered bearing had corroded away due to seawater ingestion into the grease channel. Had to remove the prop whilst it was in the water (that was fun - lucky I had a diving mate who could help) and do a complete rebuild. I find when I re-grease the prop it is common for a small amount of seawater to come out of the channel. Great prop for performance, but the susceptibility to corrosion is a concern. My cutlass strut has a groove cut out of it. At higher engine revs the prop moves forward due to the flexible engine mounts which exacerbates the problem. All the best